JP2000273113A - Prepolymerization catalyst and method for polyolefin polymerization using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a prepolymerization catalyst for obtaining an extremely high stereoregular olefin polymer by prepolymerizing an olefin with a catalyst comprising a solid titanium compound, an organoaluminum compound and an organosilicon compound, and further prepolymerizing the resulting product with a catalyst comprising the organoaluminum compound and the organosilicon compound. SOLUTION: An olefin is prepolymerized with a catalyst comprising a solid titanium compound, a compound represented by formula I (wherein R1 is a 1-10C alkyl) and a compound represented by formula II (wherein R2 and R3 are each a 1-20C hydrocarbon, at least one of them being a chain hydrocarbon in which an atom directly bonding to Si is a tertiary carbon or a cyclic hydrocarbon in which the atom is a secondary carbon; R4 is a 1-3C alkyl), and further prepolymerizing the resulting product with a catalyst comprising the compound represented by formula I and a compound represented by formula III (wherein R5 and R6 are each H or methyl R7 and R8 are each a 1-4C alkyl, a 3-6C cyclic alkyl or an aryl; R9 is a 1-3C alkyl; (n) is an integer of 2-6). The prepolymerization catalyst in combination with an organoaluminum compound and an electron donor is used for the polymerization of the olefin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel olefin prepolymerization catalyst and a method for polyolefin polymerization using the prepolymerization catalyst. Specifically, the present invention relates to a prepolymerization catalyst capable of obtaining a polymer having extremely high stereoregularity in a high yield in the polymerization of olefins, particularly α-olefins having 3 or more carbon atoms, and a method for producing the polymer.

[0002]

2. Description of the Related Art Ziegler-Natta type catalysts comprising an organoaluminum compound such as diethylaluminum chloride and trialkylaluminum and a solid titanium catalyst such as titanium trichloride and titanium tetrachloride as catalysts for the polymerization of olefins are known. It is known. Hitherto, various methods have been proposed for improving the polymerization activity and stereoregularity of this catalyst. Above all, the use of a so-called supported solid titanium catalyst containing titanium, magnesium and halogen as essential components as the solid titanium catalyst has greatly improved the polymerization activity.

However, when olefins such as propylene are polymerized using this catalyst, the activity is high,
Since the resulting polymer has extremely low stereoregularity and a large amount of atactic components, its practical value has been reduced.

In view of the above, a method has been proposed for improving stereoregularity by combining various internal donors such as esters and ethers (internal donors) with a solid titanium catalyst containing titanium, magnesium and halogen. Yes,
Further, by adding an electron donor (external donor) such as an ester, an ether, an amine or an organosilicon compound in addition to the solid titanium catalyst and the organoaluminum compound, the stereoregularity is further improved. I have.

Japanese Unexamined Patent Publication (Kokai) No. 55-75409 discloses that such a catalyst system is preliminarily polymerized with a small amount of propylene before the main polymerization, whereby not only the polymerization activity and polymer properties are improved. It is known that the stereoregularity of the polymer is also improved.

Further, JP-A-9-278819 discloses a titanium compound containing titanium, magnesium and halogen as essential components, an organoaluminum compound such as trialkylaluminum, and a substituted cyclic amino group having a 5- to 8-membered ring. Prepolymerization of the olefin in the presence of the organosilicon compound, the resulting solid titanium catalyst component and an organoaluminum compound such as trialkylaluminum,
Further, there is disclosed a method of polymerizing an olefin in the presence of an organosilicon compound containing a 5- to 8-membered substituted cyclic amino group.

Although the polyolefins obtained by this method have higher polymerization activity and stereoregularity than previously known catalysts, there is still room for improvement in these properties, and especially the high quality of molded articles. In order to satisfy various physical properties such as rigidity, high hardness, high heat resistance, and low shrinkage, further higher stereoregularity polypropylene has been desired.

[0008]

Accordingly, an object of the present invention is to provide an olefin prepolymerization catalyst capable of obtaining an olefin polymer having extremely high stereoregularity, and a method for producing a polyolefin using such a prepolymerization catalyst. Is to provide.

[0009]

The object of the present invention can be achieved by the following constitution.

That is, according to the present invention, an olefin prepolymerization (hereinafter referred to as a first-stage prepolymerization) was carried out in the presence of a polymerization catalyst comprising the following components [A], [B] and [C]. An olefin prepolymerization catalyst obtained by performing an olefin prepolymerization (hereinafter, referred to as a second-stage prepolymerization) in the presence of a prepolymer and a catalyst comprising the following components [B] and [D].

[0011] [A] component: solid titanium compound component [B]: an organoaluminum compound represented by the general formula _{^{[I] R 1 3 Al [}} I] ( where, R is an alkyl group having 1 to 10 carbon atoms. Component [C]: an organosilicon compound represented by the general formula [II] R ² R ³ Si (OR ⁴ ) ₂ [II] (where R ² and R ³ are the same or different carbon atoms having 1 to 20 carbon atoms) A hydrogen group, at least one of which is a chain hydrocarbon group having a tertiary carbon atom or a cyclic hydrocarbon group having a secondary carbon atom, and R ⁴ is an alkyl group having 13 carbon atoms. Component [D]: Organosilicon Compound Represented by General Formula [III]

[0012]

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(Where n is an integer of 2 to 6, R ⁵ ,
R ⁶ is hydrogen or a methyl group the same or different, R ^7, R
⁸ is the same or different alkyl group having 1 to 4 carbon atoms, cyclic alkyl group having 3 to 6 carbon atoms or aryl group, and R ⁹ is an alkyl group having 1 to 3 carbon atoms. The present invention also provides a method for producing a highly stereoregular polyolefin, characterized in that the olefin is polymerized in the presence of a catalyst comprising the above prepolymerized catalyst, an organoaluminum compound and an electron donor.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the solid titanium compound used in the present invention, known compounds are used without any particular limitation as long as they contain magnesium, titanium, halogen and an electron donor as essential components.

Many methods for producing such a solid titanium compound have been proposed so far. In the present invention, the solid titanium compound obtained by these known methods is used without any limitation. For example, a method in which a titanium compound such as a titanium tetrahalide is co-ground with a magnesium compound in the presence of an electron donor, a method in which a titanium compound, a magnesium compound and an electron donor are brought into contact in a solvent, and the like are exemplified.

The method for preparing these solid titanium compounds is as follows:
For details, see JP-A-56-155206 and JP-A-56-155206.
136806, 57-34103, 5
Nos. 8-8706 and 58-83006, 5
JP-A-8-138708, JP-A-58-183709, JP-A-59-206408, and JP-A-59-21931.
No. 1, No. 60-81208, No. 60-812
Nos. 09, 60-186508 and 60-1
Nos. 92708, 61-21309, 6
JP-A-271304, JP-A-62-15209,
It is disclosed in JP-A-62-1706, JP-A-62-72702, JP-A-62-104810 and the like.

As the titanium compound used for preparing the solid titanium compound, a tetravalent titanium compound is used. As such a tetravalent titanium compound, titanium halides such as tetrahalogenated titanium, tetraalkoxytitanium, trihalogenated alkoxytitanium, dihalogenated dialkoxytitanium and halogenated trialkoxytitaniums can be used. Specific examples of such compounds include tetrachlorotitanium, tetrabromotitanium, tetraiodotitanium,
Tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetra-i-propoxytitanium,
Using tetrabutoxytitanium, tetra i-butoxytitanium, tetrahexyloxytitanium, tetraoctyloxytitanium, trichloroethoxytitanium, dichlorodiethoxytitanium, triethoxychlorotitanium, trichlorobutoxytitanium, dichlorodibutoxytitanium, tributoxychlorotitanium, or the like be able to.

The magnesium compound used for the preparation of the above-mentioned solid titanium compound includes magnesium halides such as magnesium chloride, alkoxymagnesiums such as magnesium diethoxide, alkoxymagnesium halides, magnesium oxide, magnesium hydroxide, and magnesium carbonate. Acid salts and the like can be used.
Further, as the electron donor used for preparing the solid titanium compound, known electron donors are used without any particular limitation. For example, alcohols, phenols, ketones, aldehydes, carboxylic acids, organic acid halides, esters of organic or inorganic acids, ethers, acid amides, acid anhydrides, amines, nitriles, isocyanates , Ammonia and the like.

Of these, esters of organic acids are preferred, and those having two or more ester bonds in the molecule are particularly preferred.

Examples of the compound having two or more ester bonds in the molecule include diethyl succinate, dibutyl succinate, diethyl methyl succinate, and the like.
Di-i-butyl α-methylglutarate, diethyl methylmalonate, diethyl ethylmalonate, diethyl i-propylmalonate, diethylbutylmalonate, diethylphenylmalonate, diethyldiethylmalonate, diethyldibutylmalonate, monomaleic acid Octyl, dioctyl maleate, dibutyl maleate, dibutyl butyl maleate, diethyl butyl maleate, dii-propyl β-methylglutarate, diallyl ethyl succinate, di-2-ethylhexyl fumarate, diethyl itaconate, dioctyl citracone, etc. Aliphatic polycarboxylic acid esters, diethyl 1,2-cyclohexanecarboxylate,
Alicyclic polycarboxylates such as diisobutyl 1,2-cyclohexanecarboxylate, diethyl tetrahydrophthalate, diethyl nadicate, monoethyl phthalate, dimethyl phthalate, methylethyl phthalate, mono-i-butyl phthalate, phthalic acid Diethyl, ethyl i-butyl phthalate, dipropyl phthalate, dii-propyl phthalate, dibutyl phthalate, dii-butyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dineopentyl phthalate And aromatic polycarboxylic esters such as didecyl phthalate, benzyl butyl phthalate, diphenyl phthalate, diethyl naphthalene dicarboxylate, dibutyl naphthalene dicarboxylate, triethyl trimetate and dibutyl trimetate.

Other examples of the compound having two or more ester bonds in the molecule include diethyl adipate,
Di-butyl adipate, di-propyl sebacate,
Esters of long-chain dicarboxylic acids such as dibutyl sebacate, dioctyl sebacate, and di-2-ethylhexyl sebacate can be mentioned.

Of these, the use of phthalates is most preferable because it is effective in the effects of the present invention.

In the present invention, the organoaluminum compound used in the first-stage prepolymerization and the second-stage prepolymerization is a trialkylaluminum represented by the following general formula [I]. R ¹ ₃ Al [I] the above general formula [I], R ¹ is a saturated alkyl group having 1 to 10 carbon atoms. Examples of the saturated alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, i-propyl group, butyl group, i-butyl group, s-butyl group, t-butyl group, pentyl group, and i-pentyl. Group, neopentyl group,
Examples include a chain alkyl group such as a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a cyclopentyl group, and a cyclohexyl group, and a cyclic alkyl group.

Specific examples of trialkylaluminum compounds that can be particularly preferably used include, for example, trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, trii-butylaluminum, trihexylaluminum, trioctylaluminum, tridecyl Aluminum and the like can be mentioned.

The above-mentioned organoaluminum compound may contain another organoaluminum compound such as an organoaluminum halide compound as long as its action is not significantly impaired. Generally, such a ratio is 2 to organoaluminum compounds having substantially no halogen atoms.
00% by weight or less.

The organosilicon compound used in the first-stage prepolymerization of the present invention is a silicon compound represented by the following general formula [II].

R ² R ³ Si (OR ⁴ ) ₂ [II] In the above compound, R ² and R ³ are the same or different hydrocarbon groups having 1 to 20 carbon atoms, at least one of which is directly bonded to a silicon atom. A chain hydrocarbon group in which the atom is a secondary or tertiary carbon or a cyclic hydrocarbon group in which the atom is a secondary carbon. For example,
Examples of the chain hydrocarbon group in which the atom directly connected to the silicon atom is a secondary or tertiary carbon include an i-propyl group, an s-butyl group, a t-butyl group, and a t-amyl group. Examples of the cyclic hydrocarbon group in which the atom directly connected to the silicon atom is a secondary carbon include a cyclopentyl group, a 2-methylcyclopentyl group, a 3-methylcyclopentyl group, a 2-ethylcyclopentyl group, a 2-butylcyclopentyl group,
2,3-dimethylcyclopentyl group, 2,4-dimethylcyclopentyl group, 2,5-dimethylcyclopentyl group, 2,3-diethylcyclopentyl group, 2,3,4-
Trimethylcyclopentyl group, 2,3,5-trimethylcyclopentyl group, 2,3,4-triethylcyclopentyl group, tetramethylcyclopentyl group, tetraethylcyclopentyl group, cyclohexyl group, 2-methylcyclohexyl group, 3-methylcyclohexyl group, 4- Methylcyclohexyl group, 2-ethylcyclohexyl group,
2,3-dimethylcyclohexyl group, 2,4-dimethylcyclohexyl group, 2,5-dimethylcyclohexyl group, 2,6-dimethylcyclohexyl group, 2,3-diethylcyclohexyl group, 2,3,4-trimethylcyclohexyl group, 2,3,5-trimethylcyclohexyl group, 2,3,6-trimethylcyclohexyl group, 2,
4,5-trimethylcyclohexyl group, 2,4,6-trimethylcyclohexyl group, 2,3,4-triethylcyclohexyl group, 2,3,4,5-tetramethylcyclohexyl group, 2,3,4,6-tetra Methylcyclohexyl group, 2,3,5,6-tetramethylcyclohexyl group, 2,3,4,5-tetraethylcyclohexyl group,
Examples include a pentamethylcyclohexyl group and a pentaethylcyclohexyl group.

The hydrocarbon group having 1 to 20 carbon atoms includes methyl, ethyl, propyl, i-propyl, butyl, i-butyl, s-butyl, pentyl, i-pentyl. Group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, and cyclopentyl group, substituted cyclopentyl group, cyclohexyl group, substituted cyclohexyl group, t-butyl group, t-amyl group and the like as described above. No.

R ⁴ is an alkyl group having 1 to 3 carbon atoms.
Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group.

More specific examples of the organosilicon compound represented by the general formula [II] include di-i-propyldimethoxysilane, di-s-butyldimethoxysilane, di-t-butyldimethoxysilane, and di-t-butyldimethoxysilane. -Amyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, di (2-methylcyclopentyl) dimethoxysilane, di (3-methylcyclopentyl) dimethoxysilane, di (2-ethylcyclopentyl) dimethoxysilane, di (2,3- Dimethylcyclopentyl) dimethoxysilane, di (2,4-dimethylcyclopentyl) dimethoxysilane, di (2,5-dimethylcyclopentyl) dimethoxysilane, di (2,3-diethylcyclopentyl) dimethoxysilane, di (2,3
4-trimethylcyclopentyl) dimethoxysilane, di (2,3,5-trimethylcyclopentyl) dimethoxysilane, di (2,3,4-triethylcyclopentyl)
Dimethoxysilane, di (tetramethylcyclopentyl)
Dimethoxysilane, di (tetraethylcyclopentyl)
Dimethoxysilane, di (2-methylcyclohexyl) dimethoxysilane, di (3-methylcyclohexyl) dimethoxysilane, di (4-methylcyclohexyl) dimethoxysilane, di (2-ethylcyclohexyl) dimethoxysilane, di (2,3-dimethyl Cyclohexyl) dimethoxysilane, di (2,4-dimethylcyclohexyl)
Dimethoxysilane, di (2,5-dimethylcyclohexyl) dimethoxysilane, di (2,6-dimethylcyclohexyl) dimethoxysilane, di (2,3-diethylcyclohexyl) dimethoxysilane, di (2,3,4-trimethylcyclohexyl) Dimethoxysilane, di (2,
3,5-trimethylcyclohexyl) dimethoxysilane, di (2,3,6-trimethylcyclohexyl) dimethoxysilane, di (2,4,5-trimethylcyclohexyl) dimethoxysilane, di (2,4,6-trimethylcyclohexyl) dimethoxy Silane, di (2,3,4-
Triethylcyclohexyl) dimethoxysilane, di (2,3,4,5-tetramethylcyclohexyl) dimethoxysilane, di (2,3,4,6-tetramethylcyclohexyl) dimethoxysilane, di (2,3,5,6-
Tetramethylcyclohexyl) dimethoxysilane, di (2,3,4,5-tetraethylcyclohexyl) dimethoxysilane, di (pentamethylcyclohexyl) dimethoxysilane, di (pentaethylcyclohexyl) dimethoxysilane, i-propylmethyldimethoxysilane,
i-propylethyldimethoxysilane, s-butylmethyldimethoxysilane, s-butylethyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylethyldimethoxysilane, t-amylmethyldimethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane Examples thereof include silane and cyclohexylmethyldimethoxysilane.

The organosilicon compound used in the second-stage prepolymerization of the present invention is a silicon compound represented by the following general formula [III].

[0032]

Embedded image

In the general formula [III], R ⁵ and R ⁶ are the same or different hydrogen or methyl groups. R ⁷ and R ⁸ are the same or different and are a linear or branched alkyl group having 1 to 4 carbon atoms, a cyclic alkyl group or an aryl group having 3 to 6 carbon atoms.

The chain or branched alkyl group having 1 to 4 carbon atoms includes methyl, ethyl, propyl and i.
-Propyl group, butyl group, i-butyl group, s-butyl group and t-butyl group. In addition, examples of the cyclic alkyl group having 3 to 6 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Of these, a cyclopentyl group and a cyclohexyl group are particularly preferred from the viewpoint of production. The aryl group includes a phenyl group.

R ⁹ is an alkyl group having 1 to 3 carbon atoms.
Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group.

More specifically, examples of such an organosilicon compound include the following compounds.

For example, N, N'-dimethylethylenediaminodimethoxysilane, N, N'-dimethyl-1,2,2
-Dimethylethylenediaminodimethoxysilane, N,
N'-dimethyl-1,1,2,2-tetramethylethylenediaminodimethoxysilane, N, N'-diethylethylenediaminodimethoxysilane, N, N'-diethyl-1,2, -dimethylethylenediaminodimethoxysilane, N, N'-diethyl-1,1,2,2-tetramethylethylenediaminodimethoxysilane, N, N'-dipropylethylenediaminodimethoxysilane, N, N '
-Dipropyl-1,2, -dimethylethylenediaminodimethoxysilane, N, N'-dipropyl-1,1,2,
2, -tetramethylethylenediaminodimethoxysilane, N, N'-dii-propylethylenediaminodimethoxysilane, N, N'-dii-propyl-1,2, -dimethylethylenediaminodimethoxysilane, N, N'-
Di-propyl-1,1,2,2-tetramethylethylenediaminodimethoxysilane, N, N′-dibutylethylenediaminodimethoxysilane, N, N′-dibutyl-1,2, -dimethylethylenediaminodimethoxysilane, N, N′-dibutyl-1,1,2,2-tetramethylethylenediaminodimethoxysilane, N, N′-dii-butylethylenediaminodimethoxysilane,
N′-dii-butyl-1,2, -dimethylethylenediaminodimethoxysilane, N, N′-dii-butyl-1,
1,2,2, -tetramethylethylenediaminodimethoxysilane, N, N'-di-s-butylethylenediaminodimethoxysilane, N, N'-dis-butyl-1,2,-
Dimethylethylenediaminodimethoxysilane, N, N '
-Di-s-butyl-1,1,2,2-tetramethylethylenediaminodimethoxysilane, N, N'-dit-butylethylenediaminodimethoxysilane, N, N'-dit
-Butyl-1,2, -dimethylethylenediaminodimethoxysilane, N, N′-di-tert-butyl-1,1,2,2
2, -tetramethylethylenediaminodimethoxysilane, N, N'-dimethyl1,3-propanediaminodimethoxysilane, N, N'-diethyl-1,3-propanediaminodimethoxysilane, N, N'-dipropyl-
1,3-propanediaminodimethoxysilane, N, N '
-Diipropyl-1,3-propanediaminodimethoxysilane, N, N'-dibutyl-1,3-propanediaminodimethoxysilane, N, N'-dii-butyl-1,3
-Propanediaminodimethoxysilane, N, N'-dis
-Butyl-1,3-propanediaminodimethoxysilane, N, N'-di-tert-butyl-1,3-propanediaminodimethoxysilane, N, N'-dimethyl-2-methyl-
1,3-propanediaminodimethoxysilane, N, N '
-Diethyl-2-methyl-1,3-propanediaminodimethoxysilane, N, N'-dipropyl-2-methyl-1,3-propanediaminodimethoxysilane, N,
N'-dii-propyl-2-methyl-1,3-propanediaminodimethoxysilane, N, N'-dibutyl-2-
Methyl-1,3-propanediaminodimethoxysilane,
N, N'-dii-butyl-2-methyl-1,3-propanediaminodimethoxysilane, N, N'-dis-butyl-2-methyl-1,3-propanediaminodimethoxysilane, N, N ' -Di-tert-butyl-2-methyl-1,3-
Propanediaminodimethoxysilane, N, N'-dimethyl-2,2-dimethyl-1,3-propanediaminodimethoxysilane, N, N'-diethyl-2,2-dimethyl-1,3-propanediaminodimethoxysilane, N ,
N'-dipropyl-2,2-dimethyl-1,3-propanediaminodimethoxysilane, N, N'-dii-propyl-2,2-dimethyl-1,3-propanediaminodimethoxysilane, N, N'- Dibutyl-2,2-dimethyl-1,3-propanediaminodimethoxysilane, N,
N′-dii-butyl-2,2-dimethyl-1,3-propanediaminodimethoxysilane, N, N′-dis-butyl-2,2-dimethyl-1,3-propanediaminodimethoxysilane, N, N′-di-tert-butyl-2,2-dimethyl-1,3-propanediaminodimethoxysilane,
N, N'-dimethyl-1,4-butanediaminodimethoxysilane, N, N'-diethyl-1,4-butanediaminodimethoxysilane, N, N'-dipropyl-1,4-
Butanediaminodimethoxysilane, N, N'-dii-propyl-1,4-butanediaminodimethoxysilane,
N, N'-dibutyl-1,4-butanediaminodimethoxysilane, N, N'-diibutyl-1,4-butanediaminodimethoxysilane, N, N'-dis-butyl-1,
4-butanediaminodimethoxysilane, N, N'-di-t
-Butyl-1,4-butanediaminodimethoxysilane,
N, N′-dimethyl-1,5-pentanediaminodimethoxysilane, N, N′-diethyl-1,5-pentanediaminodimethoxysilane, N, N′-dipropyl-1,
5-pentanediaminodimethoxysilane, N, N'-dii-propyl-1,5-pentanediaminodimethoxysilane, N, N'-dibutyl-1,5-pentanediaminodimethoxysilane, N, N'-dii- Butyl-1,5-
Pentanediaminodimethoxysilane, N, N'-dis-
Butyl-1,5-pentanediaminodimethoxysilane,
N, N'-di-tert-butyl-1,5-pentanediaminodimethoxysilane, N, N'-dimethyl-1,6-hexanediaminodimethoxysilane, N, N'-diethyl-
1,6-hexanediaminodimethoxysilane, N, N '
-Dipropyl-1,6-hexanediaminodimethoxysilane, N, N'-dii-propyl-1,6-hexanediaminodimethoxysilane, N, N'-dibutyl-1,6
-Hexanediaminodimethoxysilane, N, N'-dii
-Butyl-1,6-hexanediaminodimethoxysilane, N, N'-di-s-butyl-1,6-hexanediaminodimethoxysilane, N, N'-di-t-butyl-1,6
-Hexanediaminodimethoxysilane, N, N'-dicyclopropylethylenediaminodimethoxysilane, N,
N'-dicyclobutylethylenediaminodimethoxysilane, N, N'-dicyclopentylethylenediaminodimethoxysilane, N, N'-dicyclohexylethylenediaminodimethoxysilane, N, N'-diphenylethylenediaminodimethoxysilane, and the like.

Among them, N, N'-dimethylethylenediaminodimethoxysilane, N, N'-dimethyl-1,
1,2,2-tetramethylethylenediaminodimethoxysilane, N, N′-dii-propylethylenediaminodimethoxysilane, N, N′-dimethyl-1,3-propanediaminodimethoxysilane, N, N′-dimethyl −
1,4-butanediaminodimethoxysilane, N, N'-
Dicyclopentylethylenediaminodimethoxysilane,
N, N'-dicyclohexylethylenediaminodimethoxysilane, N, N'-diphenylethylenediaminodimethoxysilane and the like are preferable.

The feature of the prepolymerization catalyst of the present invention is that the prepolymerization is obtained by prepolymerizing an olefin in two steps using the specific organosilicon compounds having different general formulas [II] and [III]. It is in. That is, in the first-stage prepolymerization, the olefin is prepolymerized in the presence of the catalyst comprising the components [A], [B], and [C], and then the first-stage prepolymerization is performed in the second-stage prepolymerization. It is obtained by prepolymerizing an olefin in two stages in the presence of a prepolymer obtained by polymerization and a catalyst comprising each of the components [B] and [D]. The prepolymerized catalyst obtained by such two-stage prepolymerization can obtain a polyolefin having remarkably high stereoregularity with respect to the prepolymerized catalyst obtained by using each organosilicon compound.

In the present invention, the first preliminary polymerization,
The second prepolymerization can be said to be a one-stage prepolymerization, even if it is performed in multiple stages, as long as the prepolymerization is performed using the same type of organosilicon compound represented by the above general formula.

In the prepolymerization of each stage of the present invention, each component of the above-mentioned catalyst may be added sequentially or may be used as a mixture. It is desirable to determine the amount of each component in the following range.

That is, in the first-stage prepolymerization and the second-stage prepolymerization, the amount of the organoaluminum compound used is determined by the ratio of Al / T to the titanium atom in the solid titanium compound.
i (molar ratio), 1 to 1000, preferably 5 to 500
It is.

The amount of the organosilicon compound represented by the general formula [II] in the first-stage prepolymerization is 0.01 to 1 in terms of a molar ratio to the organoaluminum compound.
0, preferably 0.01 to 1.0.

Further, the amount of the organosilicon compound represented by the general formula [III] in the second-stage prepolymerization is 0.01 to 1 in terms of a molar ratio to the organoaluminum compound.
0, preferably 0.01 to 1.0.

The amount of the olefin polymerized in each prepolymerization was 0.1 to 1 per gram of the solid titanium compound component.
It is preferably a pure range of 00 g, preferably 1 to 100 g, and industrially, particularly preferably a range of 2 to 50 g.

The olefin used in each prepolymerization includes olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methylbutene-1, and 4-methylpentene-1. The above-mentioned olefins can be used simultaneously in two or more types, and different olefins can be used arbitrarily in each prepolymerization.However, in consideration of the improvement in stereoregularity of the obtained polymer, one type of olefin is used. It is preferable to use 90 mol% or more, preferably 97 mol% or more. It is also possible to make hydrogen coexist in the preliminary polymerization.

Further, each prepolymerization has a polymerization rate of 0.001.
To 1.0 g-polymer / g-catalyst-minute. In order to achieve such a polymerization rate, usually,
Slurry polymerization is most preferably employed. In this case, a saturated aliphatic hydrocarbon or an aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene, and toluene can be used alone or in combination.

In the present invention, each prepolymerization temperature is generally preferably from -20 to 100 ° C., particularly preferably from 0 to 60 ° C., and may be carried out under different temperature conditions in each stage of the prepolymerization. Further, the polymerization time may be appropriately determined according to the polymerization temperature and the polymerization amount, and the polymerization pressure in the preliminary polymerization is not limited, but in the case of slurry polymerization, it is generally from atmospheric pressure to 5 k.
g / cm ² .

The prepolymerized product obtained by the first-stage prepolymerization and the prepolymerized catalyst of the present invention obtained by the second-stage prepolymerization are each washed and removed with a suitable solvent after the completion of the prepolymerization. It is desirable to do. As such a solvent, a saturated aliphatic hydrocarbon or an aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene, and toluene can be used alone or as a mixture. In addition, the number of times of washing is usually preferably 3 to 6 times.

In the present invention, each prepolymerization may be carried out in any of batch, semi-batch and continuous methods.

Although the prepolymerization method has been described above mainly on slurry polymerization, it is also possible to carry out the prepolymerization by gas phase polymerization or solventless polymerization. Preliminary polymerization may be performed by determining the conditions.

In the prepolymerization of the present invention, at each stage of the prepolymerization, the solid titanium compound [A], the organoaluminum compound [B], the organosilicon compound [C] and the nitrogen-containing organosilicon compound [D] are added. In addition, a polymer obtained by using together an iodine compound [E] represented by the following general formula [IV] R ¹⁰ -I [IV] (where R ¹⁰ is an iodine atom or a hydrocarbon group) Is preferable because the stereoregularity of the compound can be further increased.

The hydrocarbon group of R ¹⁰ has 1 to 1 carbon atoms.
And 10 alkyl groups, alkenyl groups, alkynyl groups, and aryl groups.

Examples of the iodine compound represented by the general formula [IV] include iodine, methyl iodide, ethyl iodide, propyl iodide, butyl iodide, iodobenzene,
p-Iodide toluene and the like.

Of these, methyl iodide and ethyl iodide are preferred. The amount of the iodine compound used in the prepolymerization step is I / Ti (molar ratio) with respect to the Ti atom in the titanium compound.
And 0.1 to 100, preferably 0.5 to 50.

There is provided a method for producing a polyolefin having extremely high stereoregularity using the prepolymerized catalyst of the present invention. That is, according to the present invention, the prepolymerized catalyst,
There is provided a method for producing a polyolefin, which comprises polymerizing an olefin (main polymerization) in the presence of a catalyst comprising an organoaluminum compound and an electron donor.

As the organoaluminum compound, an organoaluminum compound that can be used in each of the above prepolymerizations is used without any particular limitation.

The electron donor is, for example, an ether, an amine, an amide, a sulfur-containing compound, a nitrile, a carboxylic acid, an acid amide, or an acid anhydride for controlling the stereoregularity of an olefin having 3 or more carbon atoms. , Acid ethers, organosilicon compounds and the like are used. Among them, organosilicon compounds are preferred. As the organosilicon compound, those selected at the time of the above prepolymerization can be used.

The preferred use ratio of the above-mentioned electron donor is 0.01 to 1.
It is in the range of 0. Further, the polymerization temperature is 20 to 200 ° C,
Preferably it is 50-150 degreeC, and hydrogen can also be made to coexist as a molecular weight regulator. Further, the polymerization can be applied to slurry polymerization, solventless polymerization, and gas phase polymerization, and may be any of a batch system, a semi-batch system, and a continuous system. Further, the polymerization may be performed in two or more stages under different conditions. Can also.

Examples of the olefin used in the main polymerization include α-olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, and 4-methylpentene-1. Can be used alone or as a mixture of two or more. However, when two or more types of olefins are used, it is preferred that the specific type be used in an amount of 90 mol% or more, preferably 97 mol% or more, and particularly 99 mol% or more, from the viewpoint of improving the stereoregularity of the obtained polyolefin. preferable.

[0061]

The olefin prepolymerization catalyst of the present invention comprises:
A polyolefin having high stereoregularity can be efficiently produced. Further, the polyolefin obtained by using the prepolymerized catalyst of the present invention has excellent properties such as high rigidity, high heat resistance, high hardness, and low heat shrinkage due to its high stereoregularity.

[0062]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

The measuring methods used in the following examples and comparative examples are as follows.

(1) Melt Index (hereinafter abbreviated as MI) This was based on ASTM D-1238.

(2) Soluble amount of p-xylene 1 g of the polymer was added to 100 cc of p-xylene, the temperature was raised to 120 ° C. with stirring, and the mixture was further stirred for 30 minutes to completely dissolve the polymer. Thereafter, the p-xylene solution was left at 23 ° C. for 24 hours. The precipitate was separated by filtration, and the p-xylene solution was completely concentrated to obtain a soluble component.

Room temperature p-xylene solubles (%) = (p-xylene solubles (g) / 1 g of polymer) × 100.

(3) Main elution peak position (hereinafter abbreviated as Tmax) and half-width (hereinafter abbreviated as δ) of the main elution peak by temperature-elution fractionation The temperature-elution fractionation method is called Journal of Appl.
ied Polymer Science; Appli
ed Polymer Symposium45,1-
24 (1990).
In this method, polyolefin such as polypropylene is separated based on the distribution of crystallinity, that is, the difference in dissolution temperature in a solvent. Specifically, a sample solution is introduced into a column using Chromosolve as a packing material, the sample is adsorbed on the surface of the packing material, and then eluted with ortho-dichlorobenzene while increasing the column temperature. It can be measured by detecting the resulting polymer concentration.

The measurement temperature range is set within a range in which the entire amount of the polymer is eluted. The measurement temperature of the polypropylene as an object of the present invention is 10 to 140 ° C.
Range.

The measurement in this example was carried out using SSC-7300 manufactured by Senshu Scientific Co., under the conditions of solvent: o-dichlorobenzene, flow rate: 2 ml / min, heating rate: 4 ° C./Hr, column: 30 mm × 300 mm. went.

FIG. 1 shows a model of an analysis chart of Tmax and δ according to the temperature rising elution fractionation method.

In the analysis chart consisting of the elution curve prepared by the above-mentioned temperature-elution fractionation method, the main elution peak position (Tmax) indicates the elution temperature (° C.) of the maximum peak position, and the half-value width of the main elution peak (Tmax). δ) is Tma
Halve the peak height of the elution curve at x (a / a)
The width (temperature (° C.)) of the elution curve crossing the horizontal axis of the weight fraction at two points.

The Tmax indicates the property relating to the stereoregularity of the component most frequently present in the crystalline component of the obtained polyolefin, and the δ indicates the property relating to the distribution of the crystalline component of the obtained polyolefin.

(4) Molecular weight distribution (hereinafter abbreviated as Mw / Mn) The weight average molecular weight (Mw) and number average molecular weight (Mw) were determined by GPC (gel permeation chromatography).
n) was measured and determined. The measurement was performed by Senshu Kagaku SSC
According to -7100, the reaction was carried out at 135 ° C. using o-dichlorobenzene as a solvent.

Example 1 [Preparation of solid titanium compound] A solid titanium compound was prepared according to the method of Example 1 in JP-A-58-83006. That is, anhydrous magnesium chloride 0.95
g (10 mmol), 10 ml of decane, and 4.7 ml (30 mmol) of 2-ethylhexyl alcohol were heated and stirred at 125 ° C. for 2 hours, and then 0.55 g of phthalic anhydride was added to this solution.
(6.75 mmol) was added and the mixture was further stirred and mixed at 125 ° C. for 1 hour to obtain a homogeneous solution. After cooling to room temperature,
40 ml of titanium tetrachloride (0.36 mol
During l), the entire amount was dropped over 1 hour. After completion of the charging, the temperature of the mixed solution was raised to 110 ° C. over 2 hours, and when the temperature reached 110 ° C., 0.54 ml (2.5 mmol) of di-i-butyl phthalate was added, and the same was continued for 2 hours. It was kept under stirring at a warm temperature. After completion of the reaction for 2 hours, a solid portion was collected by hot filtration, and the solid portion was resuspended in 200 ml of TiCl ₄ , and then heated again at 110 ° C. for 2 hours. After completion of the reaction, a solid portion was collected again by hot filtration,
Washing was sufficiently performed with decane and hexane until no free titanium compound was detected in the washing solution. The composition of the solid Ti catalyst was 2.1% by weight of titanium, 57% by weight of chlorine, 18.0% by weight of magnesium, and 2% of di-i-butyl phthalate.
It was 1.9% by weight.

[Preliminary polymerization] 1 l of N ₂ -substituted
After charging 200 ml of purified hexane, 50 mmol of triethylaluminum, 10 mmol of dicyclopentyldimethoxysilane, 50 mmol of ethyl iodide and 5 mmol of a solid titanium catalyst component in terms of Ti atom, into a toclave,
Propylene was continuously introduced into the autoclave at a rate of 3 g per 1 g of the solid catalyst component for 30 minutes, and the first-stage prepolymerization was performed. The temperature during this period was kept at 10 ° C. After 30 minutes, the reaction was stopped, and the inside of the autoclave was sufficiently replaced with N ₂ . The solid part of the obtained slurry was washed four times with purified hexane. Further, this solid component was charged into a 1-liter autoclave subjected to N ₂ substitution, and purified hexane 2
00 ml, triethylaluminum 50 mmol, N,
N'-dimethylethylenediaminodimethoxysilane 10
After adding 50 mmol of ethyl iodide, propylene was further introduced into the autoclave continuously for 30 minutes so that the amount became 3 g per 1 g of the solid titanium catalyst component, and the second-stage prepolymerization was performed. The temperature during this period was kept at 10 ° C. After 30 minutes, the reaction was stopped, and the inside of the autoclave was sufficiently replaced with N ₂ . The solid part of the obtained slurry was washed four times with purified hexane to obtain a preliminary polymerization catalyst.

[Polymerization] Into an autoclave having an internal volume of 2 liters and subjected to N ₂ substitution, 1.0 liter of propylene was charged, and 1.1 mmol of triethylaluminum, 1.1 mmol of dicyclopentyldimethoxysilane, and hydrogen gas were further vapor-phased. After charging so as to have a medium gas concentration of 1 mol%, the internal temperature of the autoclave was raised to 65 ° C., and the prepolymerized catalyst obtained by the above-mentioned auxiliary polymerization was 4.38 × 10 ⁻³ m as Ti atoms.
mol. Subsequently, the internal temperature of the autoclave was set to 70 ° C.
And the polymerization was carried out for 1 hour. After the polymerization was completed, unreacted propylene was purged to obtain a white granular polymer.
The obtained polymer was subjected to vacuum drying at 70 ° C. for 1 hour.
The results are shown in Table 1.

Examples 2 to 6 Instead of N, N'-dimethylethylenediaminodimethoxysilane used in the second-stage prepolymerization, N, N'-dimethyl-1,1,2,2-tetramethylethylenediaminosilane was used. Dimethoxysilane (Example 2), N, N′-dii-propylethylenediaminodimethoxysilane (Example 3),
N, N'-dimethyl-1,3-propanediaminodimethoxysilane (Example 4), N, N'-dicyclohexylethylenediaminodimethoxysilane (Example 5),
The same operation as in Example 1 was performed except that N'-diphenylethylenediaminodimethoxysilane (Example 6) was used. The results are shown in Table 2.

Comparative Example 1 With respect to the organosilicon compound used in the prepolymerization of Example 1, N, N′-dimethylethylenediaminodimethoxysilane was used for the first-stage prepolymerization and dicyclopentyldimethoxysilane was used for the second-stage prepolymerization. The same operation as in Example 1 was performed except for the operation. The results are shown in Table 1.

Comparative Example 2 In the prepolymerization of Example 1, N,
The same operation as in Example 1 was performed except that the same dicyclopentyldimethoxysilane used in the first-stage prepolymerization was used instead of N'-dimethylethylenediaminodimethoxysilane. The results are shown in Table 1.

Comparative Example 3 In the prepolymerization of Example 1, the same N, N'-dimethylethylenediaminodimethoxysilane used in the second stage prepolymerization was used instead of dicyclopentyldimethoxysilane in the first stage prepolymerization. The same operation as in Example 1 was performed except for the operation. The results are shown in Table 1.

Comparative Example 4 The same operation as in Example 1 was carried out except that in the prepolymerization of Example 1, two-stage prepolymerization was not carried out. The results are shown in Table 1.

Comparative Example 5 In the prepolymerization of Example 1, N, N ′ was used instead of dicyclopentyldimethoxysilane used in the first-stage prepolymerization.
Using dimethylethylenediaminodimethoxysilane,
The same operation as in Example 1 was performed except that the second-stage prepolymerization was not performed. The results are shown in Table 1.

[0083]

[Table 1]

Examples 7 to 10 In the prepolymerization of Example 1, the amounts of the prepolymerization in the first and second stages were respectively set at the ratios shown in Table 2.
The same operation as described above was performed. Table 2 shows the results.

[0085]

[Table 2]

Examples 11 and 12 In Example 1, di-i-propyldimethoxysilane (Example 11) and t-butylethyldimethoxysilane (Example 1) were used in place of dicyclopentyldimethoxysilane used in the polymerization of the first-stage prepolymerization. The same operation as in Example 1 was performed except that Example 12) was used. The results are shown in Table 3.

Comparative Example 7 N, N'-dimethylethylenediaminodimethoxysilane was used for the first-stage prepolymerization, and di-i-propyldimethoxysilane was used for the second-stage prepolymerization of the organosilicon compound used in the prepolymerization of Example 11. The same operation as in Example 11 was performed except that was used. The results are shown in Table 3.

Comparative Example 8 Of the organosilicon compound used in the prepolymerization of Example 12, N, N'-dimethylethylenediaminodimethoxysilane was used for the first-stage prepolymerization and t-butylethyldimethoxysilane was used for the second-stage prepolymerization. The same operation as in Example 12 was performed except that was used. The results are shown in Table 3.

[0089]

[Table 3]

[Brief description of the drawings]

FIG. 1 is an analysis chart of T _max and δ according to a temperature rising elution fractionation method.

FIG. 2 is a flowchart showing a typical polymerization means of the present invention.

Continued on the front page F-term (reference) 4J028 AA01A AB01A AC04A AC05A AC06A AC07A BA00A BA03B BB00A BB01B BC15B BC34B BC39B CA16A CB12C CB27C CB35A CB36A CB62C CB66C CB81C 03 EB EE EB EB 03 EB03 EB 03 GA12 GB01

Claims (2)

[Claims] 1. Preliminary polymerization of an olefin is carried out in the presence of a polymerization catalyst comprising the following components [A], [B] and [C], and the obtained prepolymer is mixed with the following components [B] and [D]. Prepolymerization catalyst obtained by performing prepolymerization of olefin in the presence of a catalyst. [A] component: solid titanium compound component [B]: an organoaluminum compound represented by the general formula _{^{[I] R 1 3 Al [}} I] [( where, R ¹ is an alkyl group having 1 to 10 carbon atoms.) Component C]: an organosilicon compound represented by the general formula [II] R ² R ³ Si (OR ⁴ ) ₂ [II] (where R ² and R ³ are the same or different hydrocarbon groups having 1 to 20 carbon atoms) At least one of which is a chain hydrocarbon group in which the atom directly connected to the silicon atom is tertiary carbon or a cyclic hydrocarbon group in which the atom is secondary carbon, and R ⁴ is an alkyl group having 1 to 3 carbon atoms. Component [D]: an organosilicon compound represented by the general formula [III] (Where n is an integer of 2 to 6, R ⁵ and R ⁶ are the same or different hydrogen or methyl groups, and R ⁷ and R ⁸ are the same or different alkyl groups having 1 to 4 carbon atoms, A cyclic alkyl group or an aryl group having 3 to 6 carbon atoms, and R ⁹ is an alkyl group having 1 to 3 carbon atoms.) 2. A process for producing a polyolefin, comprising polymerizing an olefin in the presence of the catalyst comprising the prepolymerized catalyst, the organoaluminum compound and the electron donor according to claim 1.